Non Destructive noise on masks

Non Destructive noise on masks

Post by Mark_Reyno.. » Thu, 29 Jan 2009 08:02:15

People doing high-end retouching often apply noise to layer masks. This is to avoid posterisation and printing errors. Especially necessary on very high or low key areas. A way to non-destructuvely add noise to masks would be appreciated.

A further option to soften this noise, which would provide the capability to non-destructively'grain' the mask.

This would all be in addition to the existng feather feature, which has its uses. At the moment you can't apply noise or even rasterise this 'feather' makes the feature less useful than it should be.


Non Destructive noise on masks

Post by Chris_.. » Thu, 29 Jan 2009 09:04:28

Mark - I need to see an example. How much noise, what kind of grain are you looking for, etc. Some of that might be able to tie into the new masks panel. But I need more details to figure it out.


Non Destructive noise on masks

Post by Mark_Reyno.. » Sat, 31 Jan 2009 00:27:26

Chris The way this is normally achieved at present is to set up a series of Noise Patterns. These patterns are created using values 2, 4, 6, 8 - Gaussian Noise. The Noise is in these patterns is ideally blurred by a factor of 2 to 4 pixels. A 45 degree Motion Blur can be used for this, simulating the offset of film grain.

This grain pattern, noise plus slight blur, is filled onto the channel, and blended (Faded) using Soft Light or Overlay blend. There is a slight levels adjustment taking off the top and bottom 1% or - this eliminates the "scum dot" in the highlight and shadow of the mask.

I will get together a visual sample for you and link to it when i get time.


Non Destructive noise on masks

Post by Chris_.. » Sat, 31 Jan 2009 07:35:07

Mark - yeah, we need something concrete to examine and discuss here.
(I have to communicate the idea to people who don't think in math :-)

Non Destructive noise on masks

Post by Mark_Reyno.. » Sat, 31 Jan 2009 21:49:26

Ok did a bit of work on this one yesterday - this is a visual of the type of grain. Two sample masks, before and after


Thinking this through I came with an idea to try and keep it simple - how to link the blur to the noise factor in the interface. Perhaps not exactly like this, but with some softening control attached to the slider itself so that its not necessary to create two new controls.


Please note the wonderful waste-free panel design, and that the ludicrous invert button has been left off.


Non Destructive noise on masks

Post by christoph_pfaffenbich.. » Sun, 01 Feb 2009 00:31:40

Actually I would rank the ability to Smart Object-ify masks higher, as mentioned in a thread Mark also posted in:

Not that Im against adding Noise-capabilities to or otherwise improving the Masks Panel, but the other option would meet my masking needs better.


Non Destructive noise on masks

Post by Chris_.. » Sun, 01 Feb 2009 04:34:27

Mark - ok, that's more noise than I thought. But now we have some idea what you're looking for.

Non Destructive noise on masks

Post by Mark_Reyno.. » Tue, 03 Feb 2009 03:40:18

This would have to include some kind of controllable 'amount' slider to be useful I think. The same noise factor in the example above applied to transitional areas (hair for example) appears visually a lot less severe. In practice though, its generally where smooth gradients are included in the mask, on light ink and heavy ink areas, that posterisation happens.

Another thing I was hoping for in the masks panel was a button maybe for Channel Mixing or Calculations capabilities (modal dialogs if it makes things smoother). Calculations and Apply Image are in great need of an update. I'll post yet another thread eventually about this.

Christoph - I think what we meant in the feature request that you made, was non-destructive filtering of masks. And I agree in a perfect world that would be a better option, although I don't see it happening in the short term.


Non Destructive noise on masks

Post by progr.. » Wed, 11 Feb 2009 22:27:00

As well as noise, getting adjustment layers on layer masks (with their own masks) would be lovely.

It would save having to hold layer masks in channel form should the adjustment not be correct.

Even better would be being able to apply smart filters to them. As time goes on, it becomes more important to hold as much of an image parametrically as one can, as sometimes it's simply a case of finding out what works, and being non-destructive would be so helpful.


Non Destructive noise on masks

Post by Chris_.. » Thu, 12 Feb 2009 05:14:16

Please keep feature requests separate - so we can track and comment on them.